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Diabetic Ketoacidosis - University of Pittsburgh

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Diabetic Ketoacidosis
Abdelaziz Elamin
Professor of Pediatric Endocrinology
University of Khartoum, Sudan
Introduction
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DKA is a serious acute complications of Diabetes
Mellitus. It carries significant risk of death and/or
morbidity especially with delayed treatment.
The prognosis of DKA is worse in the extremes of
age, with a mortality rates of 5-10%.
With the new advances of therapy, DKA mortality
decreases to > 2%. Before discovery and use of
Insulin (1922) the mortality was 100%.
Epidemiology
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DKA is reported in 2-5% of known type 1
diabetic patients in industrialized countries,
while it occurs in 35-40% of such patients in
Africa.
DKA at the time of first diagnosis of diabetes
mellitus is reported in only 2-3% in western
Europe, but is seen in 95% of diabetic children
in Sudan. Similar results were reported from
other African countries .
Consequences
The latter observation is annoying because it
implies the following:
пѓ� The late diagnosis of type 1 diabetes in many
developing countries particularly in Africa.
пѓ� The late presentation of DKA, which is
associated with risk of morbidity & mortality
пѓ� Death of young children with DKA
undiagnosed or wrongly diagnosed as malaria or
meningitis.
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Pathophysiology
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Secondary to insulin deficiency, and the action of
counter-regulatory hormones, blood glucose
increases leading to hyperglycemia and glucosuria.
Glucosuria causes an osmotic diuresis, leading to
water & Na loss.
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In the absence of insulin activity the body
fails to utilize glucose as fuel and uses fats
instead. This leads to ketosis.
Pathophysiology/2
пЃ±The excess of ketone bodies will cause metabolic
acidosis, the later is also aggravated by Lactic
acidosis caused by dehydration & poor tissue
perfusion.
пЃ±Vomiting due to an ileus, plus increased insensible
water losses due to tachypnea will worsen the state
of dehydration.
пЃ±Electrolyte abnormalities are 2ry to their loss in
urine & trans-membrane alterations following
acidosis & osmotic diuresis.
Pathophysiology/3
пЃ±Because of acidosis, K ions enter the circulation
leading to hyperkalemia, this is aggravated by
dehydration and renal failure.
пЃ± So, depending on the duration of DKA, serum K
at diagnosis may be high, normal or low, but the
intracellular K stores are always depleted.
пЃ± Phosphate depletion will also take place due to
metabolic acidosis.
пЃ± Na loss occurs secondary to the hyperosmotic
state & the osmotic diuresis.
Pathophysiology/4
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The dehydration can lead to decreased kidney
perfusion and acute renal failure.
Accumulation of ketone bodies contributes to
the abdominal pain and vomiting.
The increasing acidosis leads to acidotic
breathing and acetone smell in the breath and
eventually causes impaired consciousness and
coma.
Precipitating Factors
пЃ±New onset of type 1 DM: 25%
пЃ±Infections (the most common cause): 40%
пЃ±Drugs: e.g. Steroids, Thiazides, Dobutamine &
Turbutaline.
пЃ±Omission of Insulin: 20%. This is due to:
пѓ� Non-availability (poor countries)
пѓ� fear of hypoglycemia
пѓ� rebellion of authority
пѓ� fear of weight gain
пѓ� stress of chronic disease
DIAGNOSIS
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You should suspect DKA if a diabetic
patient presents with:
пѓ�
Dehydration.
Acidotic (Kussmaul’s) breathing, with a fruity
smell (acetone).
Abdominal pain &\or distension.
Vomiting.
An altered mental status ranging from
disorientation to coma.
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DIAGNOSIS/2
To diagnose DKA, the following criteria must be
fulfilled :
Hyperglycemia: of > 300 mg/dl & glucosuria
2.
Ketonemia and ketonuria
3.
Metabolic acidosis: pH < 7.25, serum
bicarbonate < 15 mmol/l. Anion gap >10.
Anion gap= [Na]+[K] – [Cl]+[HCO3].
This is usually accompanied with severe
dehydration and electrolyte imbalance.
1.
Management
The management steps of DKA includes:
пЃ±Assessment of causes & sequele of DKA by taking a
short history & performing a scan examination.
пЃ±Quick diagnosis of DKA at the ER.
пЃ±Baseline investigations.
пЃ±Treatment, Monitoring & avoiding complications.
пЃ±Transition to outpatient management.
Assessment
пЃ± History:
Symptoms of hyperglycemia, precipitating factors ,
diet and insulin dose.
пЃ± Examination:
пѓ� Look for signs of dehydration, acidosis, and
electrolytes imbalance, including shock,
hypotension, acidotic breathing, CNS status…etc.
пѓ� Look for signs of hidden infections (Fever
strongly suggests infection) and If possible, obtain
accurate weight before starting treatment.
Quick Diagnosis
Known diabetic children confirm D
hyperglycemia, K ketonuria & A acidosis.
пЃ± Newly diagnosed diabetic children be careful not
to miss because it may mimic serious infections
like meningitis.
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пЃ±
Both Hyperglycemia (using glucometer)
glycosuria, & ketonuria (with strips) must be done
in the ER and treatment started, without waiting
for Lab results which may be delayed.
Baseline Investigations
The initial Lab evaluation includes:
пЃ± Plasma & urine levels of glucose & ketones.
пЃ± ABG, U&E (including Na, K, Ca, Mg, Cl, PO4,
HCO3), & arterial pH (with calculated anion gap).
пЃ± Venous pH is as accurate as arterial (an error of
0.025 less than arterial pH)
пЃ± Complete Blood Count with differential.
� Further tests e.g., cultures, X-rays…etc , are done
when needed.
Pitfalls in DKA
пЃ± High WCC: may be seen in the absence of
infections.
пЃ± BUN: may be elevated with prerenal azotemia
secondary to dehydration.
пЃ± Creatinine: some assays may cross-react with
ketone bodies, so it may not reflect true renal
function.
пЃ± Serum Amylase: is often raised, & when there is
abdominal pain, a diagnosis of pancreatitis may
mistakenly be made.
Treatment
Principles of Treatment:
пЃ± Careful replacement of fluid deficits.
пЃ± Correction of acidosis & hyperglycemia via
Insulin administration.
пЃ± Correction of electrolytes imbalance.
пЃ± Treatment of underlying cause.
пЃ± Monitoring for complications of treatment.
пЃ±Manage DKA in the PICU. If not available it can
be managed in the special care room of the
pediatric inpatient ward.
Fluids replacement
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Determine hydration status:
A. Hypovolemic shock:
administer 0.9% saline, Ringer’s lactate or a plasma
expander as a bolus dose of 20-30 ml/kg. This can
be repeated if the state of shock persists. Once the
patient is out of shock, you go to the 2nd step of
management.
Fluids replacement/2
B- Dehydration without shock:
1.
Administer 0.9% Saline 10 ml/kg/hour for an
initial hour, to restore blood volume and renal
perfusion.
2. The remaining deficit should be added to the
maintenance, & the total being replaced over 3648 hours. To avoid rapid shifts in serum
osmolality 0.9% Saline can be used for the initial
4-6 hours, followed by 0.45% saline.
Fluids replacement/3
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When serum glucose reaches 250mg/dl
change fluid to 5% dextrose with 0.45 saline,
at a rate that allow complete restoration in
48 hours, & to maintain glucose at 150250mg/dl.
Pediatric saline 0.18% Na Cl should not be
used even in young children.
Insulin Therapy
пЃ±start infusing regular insulin at a rate of
0.1U/kg/hour using a syringe pump. Optimally,
serum glucose should decrease in a rate no faster
than 100mg/dl/hour.
пЃ±If serum glucose falls < 200 prior to correction
of acidosis, change IV fluid from D5 to D10, but
don’t decrease the rate of insulin infusion.
пЃ±The use of initial bolus of insulin (IV/IM) is
controversial.
Insulin Therapy/2
Continue the Insulin infusion until acidosis is
cleared:
пѓ� pH > 7.3.
пѓ� Bicarbonate > 15 mmol/l
пѓ� Normal anion gap 10-12.
Correction of Acidosis
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Insulin therapy stops lipolysis and
promotes the metabolism of ketone bodies.
This together with correction of dehydration
normalize the blood PH.
Bicarbonate therapy should not be used unless
severe acidosis (pH<7.0) results in hemodynamic
instability. If it must be given, it must infused
slowly over several hours.
As acidosis is corrected, urine KB appear to rise.
Urine KB are not of prognostic value in DKA.
Insulin Therapy/3
пѓ�If no adequate settings (i.e. no infusion or
syringe pumps & no ICU care which is the
usual situation in many developing
countries) Give regular Insulin 0.1
U/kg/hour IM till acidosis disappears and
blood glucose drops to <250 mg/dl, then us
SC insulin in a dose of 0.25 U/kg every 4
hours.
пѓ�When patient is out of DKA return to the
previous insulin dose.
Correction of Electrolyte Imbalance

Regardless of K conc. at presentation, total body K
is low. So, as soon as the urine output is restored,
potassium supplementation must be added to IV
fluid at a conc. of 20-40 mmol/l, where 50% of it
given as KCl, & the rest as potassium phosphate,
this will provide phosphate for replacement, &
avoids excess phosphate (may precipitate
hypocalcaemia) & excess Cl (may precipitate
cerebral edema or adds to acidosis).
Potassium
If K conc. < 2.5, administer 1mmol/kg of
KCl in IV saline over 1 hour. Withhold
Insulin until K conc. becomes> 2.5 and
monitor K conc. hourly.
пЃ± If serum potassium is 6 or more, do not give
potassium till you check renal function and
patients passes adequate urine.
пЃ±
Monitoring
A flow chart must be used to monitor fluid
balance & Lab measures.
пѓ� serum glucose must be measured hourly.
пѓ� electrolytes also 2-3 hourly.
пѓ� Ca, Mg, & phosphate must be measured initially
& at least once during therapy.
пѓ� Neurological & mental state must examined
frequently, & any complaints of headache or
deterioration of mental status should prompt rapid
evaluation for possible cerebral edema.
Complications
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Cerebral Edema
Intracranial thrombosis or infarction.
Acute tubular necrosis.
peripheral edema.
Cerebral Edema
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Clinically apparent Cerebral edema occurs in 1-2%
of children with DKA. It is a serious complication
with a mortality of > 70%. Only 15% recover
without permanent damage.
Typically it takes place 6-10 hours after initiation of
treatment, often following a period of clinical
improvement.
Causes of Cerebral Edema
The mechanism of CE is not fully understood, but
many factors have been implicated:
пѓ� rapid and/or sharp decline in serum osmolality
with treatment.
пѓ� high initial corrected serum Na concentration.
пѓ� high initial serum glucose concentration.
пѓ� longer duration of symptoms prior to initiation of
treatment.
пѓ� younger age.
пѓ� failure of serum Na to raise as serum glucose falls
during treatment.
Presentations of C. Edema
Cerebral Edema Presentations include:
пѓ�deterioration of level of consciousness.
пѓ� lethargy & decrease in arousal.
пѓ� headache & pupillary changes.
пѓ� seizures & incontinence.
пѓ� bradycardia. & respiratory arrest when brain
stem herniation takes place.
Treatment of C. Edema
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Reduce IV fluids
Raise foot of Bed
IV Mannitol
Elective Ventilation
Dialysis if associated with fluid overload or renal
failure.
Use of IV dexamethasone is not recommended.
The End
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